This invention relates generally to frost-free faucets and more particularly, to frost-free faucets that are self-draining.
Frost-free faucets have long been used to control a flow of water externally to a building. At least some known faucets include a shut-off valve coupled within the end of an elongated pipe, or housing, located within a wall or a warmer interior portion of the building of which the wall is a part. The shut-off valve is operated by a valve stem that extends through the housing and is coupled to a handle located on an external portion of the wall or building. The handle selectively controls the flow of water through the faucet to a spigot located externally to the building. The shut-off valve enables the flow of water to be stopped at a point within the wall or building that is upstream from the elongated pipe. Residual water that remains in the housing or elongated pipe is gravity drained from the faucet through the spigot. As such, the faucet may be used in sub-freezing environments without requiring seasonal draining and with little risk of water undesirably freezing in the faucet.
Although residual water is generally drained from such faucets, if a hose, or other flow device, is coupled to the faucet spigot, residual water in the hose and faucet may be prevented from draining. As a result, residual water trapped within the faucet between the shut-off valve and the attached hose, or other flow device, may freeze and expand when the spigot is exposed to sub-freezing temperatures. More specifically, when the temperature reaches sub-freezing, as trapped residual water freezes, the expansion of the frozen water increases the pressure on the inside of the faucet. Depending on the amount of water that has frozen, the pressure exerted on the inside of the housing may become greater than the pressure that the housing can withstand. Over time, such pressure may cause cracks to develop and/or may cause the faucet to fail. Moreover, depending on the damage sustained by the faucet, water may undesirably leak into the interior of the building.